This invention relates to a magnetic disc recording and/or reproducing apparatus comprising a body of revolution including a flange and a magnetic disc attached to such flange and capable of rotation, a revolution controlling mechanism to rotate such body of revolution, a rocking arm fitted at its tip end with at least one magnetic head and capable of rocking so as to allow the magnetic head to shift along the magnetic disc, and an actuator for driving such rocking arm.
Generally, in this type of magnetic disc recording and/or reproducing apparatus, the magnetic head is stopped in a damped state on a holding zone or landing zone previously defined in the magnetic memory medium (hereinafter referred to simply as the disc) when power is applied, while, when there is inputted a command for shifting the magnetic head, the magnetic head is driven by the actuator to shift floatingly on to a specified data track and kept in a floating state as it is, thus recording and/or reproducing data at the disc.
In the conventional magnetic disc recording and/or reproducing apparatuses, however, if the power is cut off due to power failure, interruption of service, conveyance for shifting location of the apparatus, etc., the operation of the actuator will be stopped and the magnetic head, brought in a free state, will find it difficult to be held securely on the landing zone. Consequently, when any vibration or impact is applied to the apparatus, the magnetic head may move vibratorily or impactively or shift its position substantially while kept in contact with the data track formed on the disc. Therefore, both of the magnetic head and disc may be damaged to shorten the life of the apparatus, or the data stored in the disc may be ruined (over a wide range, on occasion) to allow no security of such stored data.